含Li的高锌Al-Zn-Mg-Cu合金的时效行为  

Ageing Behavior of Li-Containing Al-Zn-Mg-Cu Alloy with High Content of Zn

作　　者：赵中魁[1] 周铁涛[1] 刘培英[1] 陈昌麒[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院

出　　处：《金属热处理》2003年第8期27-30,共4页Heat Treatment of Metals

基　　金：国家重点基础研究发展规划项目(G1 9990 6490 7)

摘　　要：对化学成分 (质量分数 ,% )为Al 11 8Zn 2 9Mg 2 8Cu 1 17Li的合金分别在 110℃、12 0℃、130℃、14 0℃、15 0℃、16 0℃和 180℃进行人工时效 ,并对部分试样进行透射电镜观察。结果表明 ,适量Li对高合金含量的Al Zn Mg Cu合金的沉淀相形核影响不大 ,但可抑制其长大。高的合金含量 ,可以使合金在时效过程中析出高密度细小的沉淀相 ,从而达到很高的硬度 ,但不能完全固溶于基体的合金元素在晶界形成粗大的第二相。Al-11 8Zn-2 9Mg-2 8Cu-1 17Li (in wt%) alloy w as artificially aged at 110℃,120℃,130℃,140℃,1 50℃,160℃ and 180℃ for different time respe ctively,and the sample aged at 120℃for 2 4h was observed by transmission electron microscopy (TEM).Addition of Li to Al-Z n-Mg-Cu alloy containing high alloying e lements level has little effect on the n ucleation of precipitates,but the growth of precipitates has been inhibited.Very fine precipitates with high density are present during ageing due to high alloy ing elements level,which result in highl y strengthening alloy.As the level of al loying elements is too high to be satura ted into matrix thoroughly,coarse second phases are formed in grain boundary .

关 键 词：Al-Zn—Mg—Cu合金 锂 沉淀硬化 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG156.92[金属学及工艺—金属材料]